Spatial differences, dynamic evolution, and convergence of carbon productivity in China.

China is currently developing a green economy, and improving carbon productivity (CAP) is an important part of this process. The current study applied a minimum distance to strong efficient frontier (MinDS) model to measure China's CAP. The Dagum Gini coefficient and kernel density estimation methods were further used to reveal its spatial differences and dynamic evolution, while the coefficient of variation and spatial convergence models were employed to examine its convergence characteristics. The results showed significant spatial differences in China's CAP, with primarily high and low spatial distribution characteristics in the east and west, respectively. Between-regional differences were the main sources of the overall differences. Moreover, the differences between overall, eastern, central, and western regions of China all exhibited a widening trend. Although none showed σ convergence, all had significant absolute ß spatial convergence and conditional ß spatial convergence characteristics. Collectively, the findings of this study objectively reflect the real level, distribution characteristics, and spatial convergence characteristics of CAP in China as a whole and in each region, while also providing a reference basis for achieving peak carbon neutrality.

A novel coumarin derivative-modified cellulose fluorescent probe for selective and sensitive detection of CN- in food samples.

In this work, a novel coumarin derivative-modified cellulose acetate (DCB-CA) was synthesized as a fluorescent probe for highly selective and sensitive determination of CN- in food samples. The DCB-CA was synthesized by using CA as a skeleton, and the coumarin derivative as the fluorophore. The DCB-CA obtained was characterized by different methods including FTIR, SEM, 1H-NMR, TGA and UV-vis spectroscopy. The DCB-CA exhibited a significant "turn-off" fluorescence response to CN-, accompanied by a distinct fluorescence color change from bright yellow to colorless. The detection limit of CN- using DCB-CA was calculated to be 5.8 × 10-7 M, which was much lower than the threshold limit of CN- recommended by the World Health Organization (1.9 × 10-6 M). Because of the favorable solubility and processability of the CA, the DCB-CA was easily processed into different fluorescent materials including fluorescent films and coatings. The fluorescent film obtained was also applied to the selective detection of CN-. Furthermore, the DCB-CA was successfully applied to determine CN- in food samples.

A novel coumarin derivative-grafted dialdehyde cellulose-based fluorescent sensor for selective and sensitive detection of Fe3.

A new fluorescent probe DAC-NCH with specific response to Fe3+ was synthesized via condensation reaction between dialdehyde cellulose and coumarin derivative. This probe exhibited a significant "turn-off" fluorescence response to Fe3+, accompanied by the fluorescence color change from bright pink to colorless. DAC-NCH was highly selective for Fe3+ and could achieve detection within a short time (<3 min). The detection limit of DAC-NCH for Fe3+ was determined to be as low as 91.7 nM. The complexation mechanism of DAC-NCH with Fe3+ was confirmed by Job's plot, FTIR analysis, 1H NMR titration, and density functional theory (DFT) calculations. In addition, DAC-NCH could be used for the determination of Fe3+ in actual water samples, and DAC-NCH-embedded fluorescent membrane was able to serve as a reliable platform for the detection of Fe3+.

Regional differences and convergence of green innovation efficiency in China.

Green innovation facilitates high-quality economic development and ecological environmental protection. Herein, the minimum distance to strong efficient frontier (MinDS) model was used to measure green innovation efficiencies (GIEs) of 30 Chinese provinces over a period of 21 years (2000-2020). Gini coefficient decomposition and kernel density estimation methods were used to analyze the regional differences of GIE. Spatial correlation was estimated to analyze spatial-spillover effects and spatial convergence of the GIE. China's GIE has shown an increasing trend with significant spatial differences in GIE among provinces. Regional differences and transvariation intensity are the primary sources of spatial differences in GIE. Regional differences in GIE have decreased, except for eastern regions. The results of spatial convergence estimation suggest spatial absolute and conditional convergence in all regions. Therefore, for the GIE improvement in China, the effects of economic level, industrial structure, and environmental regulations must be considered.

A Novel Schiff Base-Modified Dialdehyde Cellulose-Based Fluorescent Probe for Al3+ and Its Application in Environmental Analysis.

Cellulose is the most abundant natural polymer with good biodegradability and biocompatibility. In this paper, a novel fluorescent probe DAC-SD-NA for aluminum (Al3+ ) detection is successfully synthesized based on dialdehyde cellulose (DAC). DAC-SD-NA exhibited a remarkable "turn-on" fluorescence response to Al3+ in a wide pH range, and the fluorescence color of DAC-SD-NA solution turned from colorless to bright blue at the presence of Al3+ . The detection limit for Al3+ is computed to be 6.06×10-7 m. The reaction mechanism of DAC-SD-NA towards Al3+ is confirmed by Job's plot, X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations. In view of DAC-SD-NA exhibited good sensitivity and selectivity, it is applied to detect Al3+ in real water. What's more, DAC-SD-NA-loaded fluorescent hydrogel can serve as a convenient tool for the detection of Al3+ .